docs: def com_google_fonts_check_usweightclass(font, ttFont, style):
    """Checking OS/2 usWeightClass."""
    from fontbakery.profiles.shared_conditions import is_ttf
  
    weight_name, expected_value = expected_os2_weight(style)
    value = ttFont['OS/2'].usWeightClass
  
    if value != expected_value:
  
      if is_ttf(ttFont) and \
         (weight_name == 'Thin' and value == 100) or \
         (weight_name == 'ExtraLight' and value == 200):
        yield WARN, ("{}:{} is OK on TTFs, but OTF files with those values"
                     " will cause bluring on Windows."
                     " GlyphsApp users must set a Instance Custom Parameter"
                     " for the Thin and ExtraLight styles to 250 and 275,"
                     " so that if OTFs are exported then it will not"
                     " blur on Windows.")
      else:
        yield FAIL, ("OS/2 usWeightClass expected value for"
                     " '{}' is {} but this font has"
                     " {}.").format(weight_name, expected_value, value)
    else:
      yield PASS, "OS/2 usWeightClass value looks good!"